Here comes a sighting of the kind that I enjoy the most, because it reaches me unexpectedly and it remains as nebulous as a ghost. 

I tried to check the information against Nabokov's "Speak, Memory" (probably in ch. Three), but I haven't been able to locate it in his words and feel totally secure about the episode. However the image of an elderly lady, who always slept in a room with the windows wide open and who was once covered by snow during the night, remains as clear now as when I read it for the first time.

 

The sighting comes from G.W.Sebald, in his novel "Austerlitz" (2001), in a Portuguese translation published by the Companhia das Letras, on p.65/66. 

The narrator is telling a story he'd heard from his friend, Austerlitz, who now, for the first and only time, mentions to him several events of his childhood in Wales.

 

Austerlitz, as a young boy, lived with a Calvinist preacher and his wife Gwendolyn, in a town called Bala, close to submerged Llanwddyn. After this lady  became too ill to leave the bed to resume her daily chores, she developped the habit of dousing herself all over, at regular intervals, with snow-white talcum-powder. Soon the entire room and the upper-floor corridors of her house were covered by a greasy surface of pale dust. 

"It was only recently that I recollected this progressive whitening of the preacher's house, said Austerlitz, when I happened to read a Russian author's childhood memories who described the mania for talcum-powder which afflicted his grandmother, a lady who, although she spent most of her time lying down on a couch and nourished herself almost exclusively of wine-jello and almond-milk, kept up her strong constitution, so much so that she used to sleep with the windows of her room always wide open, and this is why, after a night of storm, she woke up beneath a blanket of snow, without having suffered from exposure to the cold."

( I cannot remember the part of wine-jello and almond-milk in Nabokov's memoirs, perhaps because I'd never heard about them before).